I can’t give accurate information on this law in Pennsylvania, but I want to point out that Michigan has a similar law, and Michigan registrants do not have to report vacations that are less than 7 days, unless they are on probation, then they will need to report that to their probation officer.
As for traveling to other states, you must learn and comply to their registry laws. For example, it is my understanding that Florida law requires all out of state registrants to report to law enforcement and be registered, regardless of how long they plan to stay in Florida. And when they leave Florida, they will remain on Florida’s sex offender registry.
It is my opinion that if someone is released from a state’s sex offender registry, they will not need to comply to other state sex offender registries if they are just visiting. I could be mistaken about this, so it would be a very good idea to find out what that state’s laws regarding this are, before visiting. However, if that person moves to live in that other state, there is a good chance they will be forced to register there if they have a prior sexual offense conviction.